Fracking Secret Sauce Contains Diesel Fuel, but why?
|February 20, 2011||Posted by karmadsen under blog, Conservation, Fracking, Groundwater and Bedrock, Groundwater Contamination, Groundwater in the News, Mining and Groundwater, Mining and Safety|
In January of this year, a Democratic congressional investigation found that shale gas mining companies had pumped large quantities of diesel fuel into underground formations during hydraulic fracturing. The investigation team reported that companies had “injected over 32 million gallons of diesel fuel or hydraulic fracturing fluids containing diesel fuel in wells in 19 states between 2005 and 2009,” in violation of the Safe Drinking Water Act.
During hydraulic fracturing, high pressure fluid is pumped into fractured bedrock to loose reserves of methane trapped in the formation. Hypothetically, diesel fuel could pose a real danger to drinking water aquifers because it contains known hazardous chemicals, including benzene, toluene, ethylbenzene, and xylenes.
From a mechanical perspective, diesel fuel serves multiple purposes in fracking fluid. As described in the open letter from the Democratic congressional investigation, rock formations with a high clay content tend to absorb fracking water and resist shattering when it is used. According to the letter, applying a hydrocarbon as the primary fracking ingredient more effective frees methane from fractures under these circumstances.
More often, a small amounts of diesel fuel is used as a carrier for other fracking ingredients that don’t dissolve well in water. In these cases, it may represents such a small percentage of the the fluid content that it poses no threat. A recent investigation by the North Dakota Mineral Resources Department found the amount of diesel in fluid used in the state to be “tiny.” Lynn Helms, the department’s director, explained that diesel fuel is a significant ingredient in fluid used in coal-bed methane fracking, but not in the type conducted in North Dakota.
Drilling companies have claimed that using high concentrations of diesel fuel is extremely rare. If this is true diesel fuel could probably be eliminated as an ingredient in fracking fluid without great economic loss. This discussion highlights the importance of legally requiring drilling companies to disclose the ingredients of their fracking fluid.